Pen



FIG. 1 is a top plan view of the entire pen showing my new design;

FIG. 2 is the bottom plan view of the entire pen;

FIG. 3 is the bottom plan view of the cap;

FIG. 4 is the front elevational view of the pen only;

FIG. 5 is the rear elevational view of the entire pen;

FIG. 6 is the left elevational view of the entire pen; the right side being a mirror image thereof; and,

FIG. 7 is the front elevational view of the entire pen. 

The ornamental design for a pen, as shown and described. 